Fibrin Fibers: Strong, Elastic and Novel Biomaterials

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

This award to University of North Carolina at Chapel Hill by the Biomaterials program in the Division of Materials Research is to study the following: 1) to determine the molecular mechanisms that control the mechanical properties of fibrin fibers using natural and genetically engineered fibrinogens where the length and the amino acid sequence of the repetitive unit are varied; and 2) to explore electrospinning in generating fibrin fibers for use in the production of multifunctional biomaterials with novel mechanical properties. Recent studies have revealed that fibrin fibers, a major protein component of blood clots, have remarkable extensibility and elasticity. These fibers form when the soluble plasma protein fibrinogen is converted to fibrin monomers by the protease thrombin. Fibrin monomers spontaneously assemble into fibers that can be crosslinked by the transglutaminase FXIIIa. To study the mechanical properties fibrin single fibers, a dual fluorescence/atomic force microscope that will be used to visual examination and mechanical manipulation of single fibers. Electrospinning of fibrin monomers will be carried out to study the generation of strong and elastic fibers. Subsequently, mechanical properties of electrospun fibrin fibers will be modified by a number of approaches such as changing the reaction conditions, adding enzyme catalysts such as transglutaminase, and incorporating composite materials. Students - doctoral, graduate and undergraduate - working on this award will acquire knowledge and skills that are relevant to material science, bioengineering, nanoscience, protein chemistry, and polymer physics. Earlier studies have revealed that fibrin fibers formed from fibrinogen, a soluble blood protein constituent, are remarkably strong and stretchy. This discovery suggested that fibrin fibers may be useful as biodegradable and biocompatible materials. The first part of the proposed study will examine the basic mechanisms that give these fibers their remarkable strength and elasticity. The second part will determine whether these fibers could be made by electrospinning, and how to use this technology to make other fibers that are useful for the production of strong and flexible fibrin based materials. Students working on this award will be exposed to an unusual educational environment where physical sciences and biological sciences are both essential. It is also anticipated that these studies will provide the basic information needed to utilize fibrin fibers in a variety of important biomaterial and biomedical applications.